A technique has recently been developed which backs up setting data associated with a plurality of air-conditioning apparatuses controlled in a centralized manner by a controller in a system so that the setting data can be reconstructed in case of loss of the setting data stored in the controller. Specifically, various setting data items used for control of the air-conditioning apparatuses stored in the controller are backed up not to a recording medium (e.g., a hard disk, a floppy disk, a CD-ROM, or a CD-RAM) but to the air-conditioning apparatuses which are controlled by the controller, such that the setting data associated with each air-conditioning apparatus is backed up to the air-conditioning apparatus or the setting data associated with all of the air-conditioning apparatuses is backed up to each of the air-conditioning apparatuses (see, for example Patent Literature 1.)
According to this technique, if the setting data, stored in the controller, associated with the air-conditioning apparatuses is lost, a memory of the controller can be reconstructed on the basis of the setting data backed up to the air-conditioning apparatuses.